Nokia 2220 Servicehandbuch
RH-42
System Module
CCS Technical Documentation
Page 16
Nokia Corporation Confidential
Issue 2 09/2003
Figure 3: Placement of keys
Power Key
All signals for the keyboard come from the UPP ASIC, except PWRONX line for the power
key signal which is connected directly to the UEM. The pressing of the PWR key grounds
the PWRONX line and the UEM generates an interrupt to UOO, which is then recognized
as a PWR key press.
key signal which is connected directly to the UEM. The pressing of the PWR key grounds
the PWRONX line and the UEM generates an interrupt to UOO, which is then recognized
as a PWR key press.
Keys
Other keys are detected so that when a key is pressed down, the metal dome connects
one S-line and one R-line of the UPP together and creates an interrupt for the SW. This
kind of detection is also known as metaldome detection. The matrix of how lines are con-
one S-line and one R-line of the UPP together and creates an interrupt for the SW. This
kind of detection is also known as metaldome detection. The matrix of how lines are con-
nected and which lines are used for different keys is described in the following table. The
S-line S0 and R-line R5 are not used at all.
S-line S0 and R-line R5 are not used at all.
where NC = Not Connected
Returns /
Scans
S0
S1
S2
S3
S4
R0
NC
NC
Send
End
NC
R1
NC
Soft left
Up
Down
Soft right
R2
NC
1
4
7
*
R3
NC
2
5
8
0
R4
NC
3
6
9
#
R5
NC
NC
NC
NC
NC
1
2
3
4
5
6
7
8
9
#
0
*
Up
Down
End
Send
S Right
S Left